Antistatic compositions and elements containing same

Abstract

Photographic base elements and radiation-sensitive elements are protected against the adverse effects resulting from accumulation of static electrical charges by incorporating therein an antistatic layer. Such layer is prepared from a coating composition comprising a hydrophilic binder, an anionic fluorinated surfactant and an inorganic nitrate.

What is claimed is: 
     
       1. A coating composition for use in forming an antistatic layer in a radiation sensitive element, said composition comprising an aqueous solution of: (a) a hydrophilic binder;   (b) an anionic fluorinated surfactant; and   (c) an inorganic nitrate.   
     
     
       2. The composition of claim 1 wherein said anionic fluorinated surfactant has the formula R--X wherein R is partly or wholly fluorinated hydrocarbon; and X is --SO 3  M, --OSO 3  M or --COOM wherein M is a monovalent cation. 
     
     
       3. The composition of claim 2 wherein R is partly or wholly fluorinated alkylene and X is --SO 3  M. 
     
     
       4. The composition of claim 1 wherein said nitrate is an alkali metal nitrate. 
     
     
       5. The composition of claim 1 wherein said anionic fluorinated surfactant is present in an amount in the range of from about 0.05 to about 5 percent, by weight, and said inorganic nitrate is present in an amount in the range of from about 5 to about 20 percent, by weight, both based on total dry solids content of said composition. 
     
     
       6. The coating composition of claim 1 additionally containing silica. 
     
     
       7. A photographic base element comprising a support coated with an antistatic layer, said antistatic layer comprising: (a) a hydrophilic binder;   (b) an anionic fluorinated surfactant; and   (c) an inorganic nitrate.   
     
     
       8. The base element of claim 7 wherein said support is a film support. 
     
     
       9. The base element of claim 7 wherein said support is a paper support. 
     
     
       10. The base element of claim 9 wherein said support is a polyolefin-coated paper support. 
     
     
       11. A radiation-sensitive element comprising: (1) a support,   (2) a radiation-sensitive, image-forming layer on one side of said support; and   (3) an antistatic layer on the other side of said support, said antistatic layer comprising:   (a) a hydrophilic binder;   (b) an anionic fluorinated surfactant; and   (c) an inorganic nitrate.   
     
     
       12. The radiation-sensitive element of claim 11 wherein said support is a polyolefin-coated paper support. 
     
     
       13. The radiation-sensitive element of claim 11 wherein said radiation-sensitive, image-forming layer is a photosensitive silver halide emulsion layer. 
     
     
       14. The radiation-sensitive element of claim 11 wherein said anionic fluorinated surfactant has the formula R--X wherein R is partly or wholly fluorinated alkylene; and X is --SO 3  M, --OSO 3  M or --COOM wherein M is a monovalent cation. 
     
     
       15. The radiation-sensitive element of claim 14 wherein said anionic fluorinated surfactant has the formula CF 3  (CF 2 ) 7  SO 3  M. 
     
     
       16. The radiation-sensitive element of claim 11 wherein said inorganic nitrate is an alkali metal nitrate. 
     
     
       17. The radiation-sensitive element of claim 16 wherein said inorganic nitrate is sodium nitrate. 
     
     
       18. A method of providing antistatic protection for a radiation sensitive element, which method comprises coating a surface of said element with an antistatic coating composition and drying said coating, said antistatic composition comprising: (a) a hydrophilic binder;   (b) an anionic fluorinated surfactant; and   (c) an inorganic nitrate.   
     
     
       19. A photographic element comprising: (1) a support;   (2) a photosensitive image-forming layer on one side of said support; and   (3) an antistatic layer on the other side of said support, said antistatic layer comprising: (a) gelatin;   (b) an anionic fluorinated surfactant having the formula CF 3  (CF 2 ) 7  SO 3  M wherein M is a monovalent cation; and   (c) an inorganic nitrate.